Homatropine

Homatropine (Equipin, Isopto Homatropine) is an anticholinergic medication that is an antagonist at muscarinic acetylcholine receptors and thus the parasympathetic nervous system. It is used in eye drops as a cycloplegic (to temporarily paralyze accommodation), and as a mydriatic (to dilate the pupil).

Homatropine

Clinical data
AHFS/Drugs.com	Monograph
MedlinePlus	a601006
ATC code	A02BX03 (WHO) S01FA05 (WHO)
Legal status
Legal status	Rx only, not FDA approved, only sold in UK
Identifiers
IUPAC name (N-Methyl-8-azabicyclo[3.2.1]oct-3-yl) 2-hydroxy-2-phenylacetate
CAS Number	87-00-3
PubChem CID	6321423
DrugBank	DB00725
ChemSpider	16498795
UNII	8QS6WCL55Z
ChEMBL	ChEMBL1233442
CompTox Dashboard (EPA)	DTXSID6044014
ECHA InfoCard	100.001.561
Chemical and physical data
Formula	C16H21NO3
Molar mass	275.348 g·mol^−1
3D model (JSmol)	Interactive image
SMILES CN3[C@H]1CC[C@@H]3C[C@@H](C1)OC(=O)C(O)c2ccccc2
InChI InChI=1S/C16H21NO3/c1-17-12-7-8-13(17)10-14(9-12)20-16(19)15(18)11-5-3-2-4-6-11/h2-6,12-15,18H,7-10H2,1H3/t12-,13+,14+,15? Key:ZTVIKZXZYLEVOL-MCOXGKPRSA-N
(what is this?)  (verify)

The related chemical compound homatropine methylbromide (methylhomatropine) is a different medication.

Homatropine is less potent than atropine and has a shorter duration of action. It is available as the hydrobromide salt.

Homatropine is also given as an atropine substitute given to reverse the muscarinic and CNS effects associated with indirect cholinomimetic (anti-AChase) administration.

Side effects

• Blurred vision
• Sensitivity to light

Contraindications

• Untreated glaucoma
• Myasthenia gravis
• Severe heart failure
• Thyrotoxicosis

References